If you compile the emacs source code using default way (that is
"./configure && make && make install"), once it has been compiled, the
program path can no longer be changed. (i.e. if you move the program and
all its data to another directory, it won't run)

But I have specific need: I need to run emacs on multiple computers and the
path is not a constant. So how can I build a portable version of emacs?

For instance, I want to put the program and all its data in a folder named
emacs, and this folder may have different path on different computers:
/media/disk/emacs or /home/xxx/emacs or ...., and I want to make it run on
those computers.